<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Queue
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Queue.php 18951 2009-11-12 16:26:19Z alexander $
 */

/**
 * Class for connecting to queues performing common operations.
 *
 * @category   Zend
 * @package    Zend_Queue
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Queue implements Countable
{
	/**
	 * Use the TIMEOUT constant in the config of a Zend_Queue
	 */
	const TIMEOUT = 'timeout';

	/**
	 * Default visibility passed to count
	 */
	const VISIBILITY_TIMEOUT = 30;

	/**
	 * Use the NAME constant in the config of Zend_Queue
	 */
	const NAME = 'name';

	/**
	 * @var Zend_Queue_Adapter_AdapterInterface
	 */
	protected $_adapter = null;

	/**
	 * User-provided configuration
	 *
	 * @var array
	 */
	protected $_options = array();

	/**
	 * Zend_Queue_Message class
	 *
	 * @var string
	 */
	protected $_messageClass = 'Zend_Queue_Message';

	/**
	 * Zend_Queue_Message_Iterator class
	 *
	 * @var string
	 */
	protected $_messageSetClass = 'Zend_Queue_Message_Iterator';

	/**
	 * @var Zend_Log
	 */
	protected $_logger = null;

	/**
	 * Constructor
	 *
	 * Can be called as
	 * $queue = new Zend_Queue($config);
	 * - or -
	 * $queue = new Zend_Queue('array', $config);
	 * - or -
	 * $queue = new Zend_Queue(null, $config); // Zend_Queue->createQueue();
	 *
	 * @param  string|Zend_Queue_Adapter|array|Zend_Config|null String or adapter instance, or options array or Zend_Config instance
	 * @param  Zend_Config|array $options Zend_Config or a configuration array
	 * @return void
	 */
	public function __construct($spec, $options = array())
	{
		$adapter = null;
		if ($spec instanceof Zend_Queue_Adapter_AdapterInterface) {
			$adapter = $spec;
		} elseif (is_string($spec)) {
			$adapter = $spec;
		} elseif ($spec instanceof Zend_Config) {
			$options = $spec->toArray();
		} elseif (is_array($spec)) {
			$options = $spec;
		}

		// last minute error checking
		if ((null === $adapter)
		&& (!is_array($options) && (!$options instanceof Zend_Config))
		) {
			require_once 'Zend/Queue/Exception.php';
			throw new Zend_Queue_Exception('No valid params passed to constructor');
		}

		// Now continue as we would if we were a normal constructor
		if ($options instanceof Zend_Config) {
			$options = $options->toArray();
		} elseif (!is_array($options)) {
			$options = array();
		}

		// Make sure we have some defaults to work with
		if (!isset($options[self::TIMEOUT])) {
			$options[self::TIMEOUT] = self::VISIBILITY_TIMEOUT;
		}

		// Make sure all defaults are appropriately set.
		if (!array_key_exists('timeout', $options)) {
			$options[self::TIMEOUT] = self::VISIBILITY_TIMEOUT;
		}
		if (array_key_exists('messageClass', $options)) {
			$this->setMessageClass($options['messageClass']);
		}
		if (array_key_exists('messageSetClass', $options)) {
			$this->setMessageSetClass($options['messageSetClass']);
		}

		$this->setOptions($options);

		// if we were passed an adapter we either build the $adapter or use it
		if (null !== $adapter) {
			$this->setAdapter($adapter);
		}
	}

	/**
	 * Set queue options
	 *
	 * @param  array $options
	 * @return Zend_Queue
	 */
	public function setOptions(array $options)
	{
		$this->_options = array_merge($this->_options, $options);
		return $this;
	}

	/**
	 * Set an individual configuration option
	 *
	 * @param  string $name
	 * @param  mixed $value
	 * @return Zend_Queue
	 */
	public function setOption($name, $value)
	{
		$this->_options[(string) $name] = $value;
		return $this;
	}

	/**
	 * Returns the configuration options for the queue
	 *
	 * @return array
	 */
	public function getOptions()
	{
		return $this->_options;
	}

	/**
	 * Determine if a requested option has been defined
	 *
	 * @param  string $name
	 * @return bool
	 */
	public function hasOption($name)
	{
		return array_key_exists($name, $this->_options);
	}

	/**
	 * Retrieve a single option
	 *
	 * @param  string $name
	 * @return null|mixed Returns null if option does not exist; option value otherwise
	 */
	public function getOption($name)
	{
		if ($this->hasOption($name)) {
			return $this->_options[$name];
		}
		return null;
	}

	/**
	 * Set the adapter for this queue
	 *
	 * @param  string|Zend_Queue_Adapter_AdapterInterface $adapter
	 * @return Zend_Queue Provides a fluent interface
	 */
	public function setAdapter($adapter)
	{
		if (is_string($adapter)) {
			if (null === ($adapterNamespace = $this->getOption('adapterNamespace'))) {
				$adapterNamespace = 'Zend_Queue_Adapter';
			}

			$adapterName = str_replace(
                ' ',
                '_',
			ucwords(
			str_replace(
                        '_',
                        ' ',
			strtolower($adapterNamespace . '_' . $adapter)
			)
			)
			);

			if (!class_exists($adapterName)) {
				require_once 'Zend/Loader.php';
				Zend_Loader::loadClass($adapterName);
			}

			/*
			 * Create an instance of the adapter class.
			 * Pass the configuration to the adapter class constructor.
			 */
			$adapter = new $adapterName($this->getOptions(), $this);
		}

		if (!$adapter instanceof Zend_Queue_Adapter_AdapterInterface) {
			require_once 'Zend/Queue/Exception.php';
			throw new Zend_Queue_Exception("Adapter class '" . get_class($adapterName) . "' does not implement Zend_Queue_Adapter_AdapterInterface");
		}

		$this->_adapter = $adapter;

		$this->_adapter->setQueue($this);

		if (null !== ($name = $this->getOption(self::NAME))) {
			$this->_setName($name);
		}

		return $this;
	}

	/**
	 * Get the adapter for this queue
	 *
	 * @return Zend_Queue_Adapter_AdapterInterface
	 */
	public function getAdapter()
	{
		return $this->_adapter;
	}

	/**
	 * @param  string $className
	 * @return Zend_Queue Provides a fluent interface
	 */
	public function setMessageClass($className)
	{
		$this->_messageClass = (string) $className;
		return $this;
	}

	/**
	 * @return string
	 */
	public function getMessageClass()
	{
		return $this->_messageClass;
	}

	/**
	 * @param  string $className
	 * @return Zend_Queue Provides a fluent interface
	 */
	public function setMessageSetClass($className)
	{
		$this->_messageSetClass = (string) $className;
		return $this;
	}

	/**
	 * @return string
	 */
	public function getMessageSetClass()
	{
		return $this->_messageSetClass;
	}

	/**
	 * Get the name of the queue
	 *
	 * Note: _setName() used to exist, but it caused confusion with createQueue
	 * Will evaluate later to see if we should add it back in.
	 *
	 * @return string
	 */
	public function getName()
	{
		return $this->getOption(self::NAME);
	}

	/**
	 * Create a new queue
	 *
	 * @param  string           $name    queue name
	 * @param  integer          $timeout default visibility timeout
	 * @return Zend_Queue|false
	 * @throws Zend_Queue_Exception
	 */
	public function createQueue($name, $timeout = null)
	{
		if (!is_string($name)) {
			require_once 'Zend/Queue/Exception.php';
			throw new Zend_Queue_Exception('$name is not a string');
		}

		if ((null !== $timeout) && !is_integer($timeout)) {
			require_once 'Zend/Queue/Exception.php';
			throw new Zend_Queue_Exception('$timeout must be an integer');
		}

		// Default to standard timeout
		if (null === $timeout) {
			$timeout = $this->getOption(self::TIMEOUT);
		}

		// Some queues allow you to create on the fly, but cannot return
		// a list of queues.  Stomp protocol for example.
		if ($this->isSupported('create')) {
			if ($this->getAdapter()->isExists($name)) {
				return false;
			}

			if (!$this->getAdapter()->create($name, $timeout)) {
				return false;
			}
		}

		$options = array(
		self::NAME  => $name,
            'timeout'   => $timeout
		);

		return new self($this->getAdapter(), $options);
	}

	/**
	 * Delete the queue this object is working on.
	 *
	 * This queue is disabled, regardless of the outcome of the deletion
	 * of the queue, because the programmers intent is to disable this queue.
	 *
	 * @return boolean
	 */
	public function deleteQueue()
	{
		if ($this->isSupported('delete')) {
			$deleted = $this->getAdapter()->delete($this->getName());
		}
		else {
			$deleted = true;
		}

		/**
		 * @see Zend_Queue_Adapter_Null
		 */
		require_once('Zend/Queue/Adapter/Null.php');
		$this->setAdapter(new Zend_Queue_Adapter_Null($this->getOptions()));

		return $deleted;
	}

	/**
	 * Delete a message from the queue
	 *
	 * Returns true if the message is deleted, false if the deletion is
	 * unsuccessful.
	 *
	 * Returns true if the adapter doesn't support message deletion.
	 *
	 * @param  Zend_Queue_Message $message
	 * @return boolean
	 * @throws Zend_Queue_Exception
	 */
	public function deleteMessage(Zend_Queue_Message $message)
	{
		if ($this->getAdapter()->isSupported('deleteMessage')) {
			return $this->getAdapter()->deleteMessage($message);
		}
		return true;
	}

	/**
	 * Send a message to the queue
	 *
	 * @param  mixed $message message
	 * @return Zend_Queue_Message
	 * @throws Zend_Queue_Exception
	 */
	public function send($message)
	{
		return $this->getAdapter()->send($message);
	}

	/**
	 * Returns the approximate number of messages in the queue
	 *
	 * @return integer
	 */
	public function count()
	{
		if ($this->getAdapter()->isSupported('count')) {
			return $this->getAdapter()->count();
		}
		return 0;
	}

	/**
	 * Return the first element in the queue
	 *
	 * @param  integer $maxMessages
	 * @param  integer $timeout
	 * @return Zend_Queue_Message_Iterator
	 */
	public function receive($maxMessages=null, $timeout=null)
	{
		if (($maxMessages !== null) && !is_integer($maxMessages)) {
			require_once 'Zend/Queue/Exception.php';
			throw new Zend_Queue_Exception('$maxMessages must be an integer or null');
		}

		if (($timeout !== null) && !is_integer($timeout)) {
			require_once 'Zend/Queue/Exception.php';
			throw new Zend_Queue_Exception('$timeout must be an integer or null');
		}

		// Default to returning only one message
		if ($maxMessages === null) {
			$maxMessages = 1;
		}

		// Default to standard timeout
		if ($timeout === null) {
			$timeout = $this->getOption(self::TIMEOUT);
		}

		return $this->getAdapter()->receive($maxMessages, $timeout);
	}

	/**
	 * Return a list of queue capabilities functions
	 *
	 * $array['function name'] = true or false
	 * true is supported, false is not supported.
	 *
	 * @param  string $name
	 * @return array
	 */
	public function getCapabilities()
	{
		return $this->getAdapter()->getCapabilities();
	}

	/**
	 * Indicates if a function is supported or not.
	 *
	 * @param  string $name
	 * @return boolean
	 */
	public function isSupported($name)
	{
		$translation = array(
            'deleteQueue' => 'delete',
            'createQueue' => 'create'
            );

            if (isset($translation[$name])) {
            	$name = $translation[$name];
            }

            return $this->getAdapter()->isSupported($name);
	}

	/**
	 * Get an array of all available queues
	 *
	 * @return array
	 * @throws Zend_Queue_Exception
	 */
	public function getQueues()
	{
		if (!$this->isSupported('getQueues')) {
			throw new Zend_Queue_Exception( __FUNCTION__ . '() is not supported by ' . get_class($this->getAdapter()));
		}

		return $this->getAdapter()->getQueues();
	}

	/**
	 * Set the name of the queue
	 *
	 * This is AN UNSUPPORTED FUNCTION
	 *
	 * @param  string           $name
	 * @return Zend_Queue|false Provides a fluent interface
	 */
	protected function _setName($name)
	{
		if (!is_string($name)) {
			/**
			 * @see Zend_Queue_Exception
			 */
			require_once 'Zend/Queue/Exception.php';
			throw new Zend_Queue_Exception("$name is not a string");
		}

		if ($this->getAdapter()->isSupported('create')) {
			if (!$this->getAdapter()->isExists($name)) {
				$timeout = $this->getOption(self::TIMEOUT);

				if (!$this->getAdapter()->create($name, $timeout)) {
					// Unable to create the new queue
					return false;
				}
			}
		}

		$this->setOption(self::NAME, $name);

		return $this;
	}

	/**
	 * returns a listing of Zend_Queue details.
	 * useful for debugging
	 *
	 * @return array
	 */
	public function debugInfo()
	{
		$info = array();
		$info['self']                     = get_class($this);
		$info['adapter']                  = get_class($this->getAdapter());
		foreach ($this->getAdapter()->getCapabilities() as $feature => $supported) {
			$info['adapter-' . $feature]  = ($supported) ? 'yes' : 'no';
		}
		$info['options']                  = $this->getOptions();
		$info['options']['driverOptions'] = '[hidden]';
		$info['currentQueue']             = $this->getName();
		$info['messageClass']             = $this->getMessageClass();
		$info['messageSetClass']          = $this->getMessageSetClass();

		return $info;
	}
}
